Disc-type wood reducer with multiple feed



Aug. 27, 1963 D. L. SCHUBERT DISC-TYPE WOOD REDUCER WITH MULTIPLE FEEDFiled April 4, 1960 2 Sheets-Sheet 1 ll 0 @Wdf b ,r m aw n Sm L. w k a zD Aug. 27, 1963 D. L. SCHUBERT 3,101,756

DISC-TYPE woon REDUCER WITH MULTIPLE FEED Filed April 4, 1960 2Sheets-Sheet 2 [E] Dale Lschuber'f' NEW HHBF.

3,101,756 DISC-TYPE WOOD REDUCER WITH MULTIPLE FEED Dale L. Schubert,Tacoma, Wash, assignor of one-half to Industrial Development Co., Inc.,Tacoma, Wash.,

a corporation of Washington Filed Apr. 4, 1960, Ser. No. 19,920 7Claims. (Cl. 144-176) This invention relates to a disc type wood reducerof the class employed particularly for reducing wood to flakes used inthe manufacture of wood composition board, although also it may beapplied to the reduction of wood to pulp mill chips and similar uses.

When making composition board from wood flakes, it is essential to theproduction of a board product having uniform properties that the flakesof which it is composed have uniform dimensions and be free from anunduly large proportion of fines and slivers. This objective isdifficult of achievement, particularly when producing flakes in largequantities from wood pieces of random sizes.

Accordingly it is the general object of the present invention to providea high-capacity, disc-type wood reducer capable of reducing wood piecesto flakes or other shapes, particularly to flakes suited for use in thelarge scale manufacture of wood composition board.

Another object of this invention is to provide wood reducing apparatusto which random size wood pieces may be fed at a high rate of speed, andwhich can be cleared of wood pieces quickly and efficiently in the eventthat the pieces become jammed in the feeding mechanism.

In the drawings:

FIG. 1 is a plan view of the herein described multiple feed disc-typewoodreducer, partly broken away to illustrate its interior construction;

FIG. 2 is a fragmentary sectional view taken along line 22 of FIG. 1 andillustrating the wood feed and reduction means on the downstroke side ofthe reducer;

FIG. 3 is a view in side elevation, partly in section, of the presentlydescribed wood reducer illustrating the wood feed and reductionapparatus on its upstroke side;

FIG. 4 is a fragmentary sectional view looking in the direction of thearrows 44 of FIG. 3 and illustrating the hold down means employed instabilizing the wood pieces as they are reduced; and

FIG. 5 is a detail sectional view illustrating an alternate constructionfor the wood stabilizing and feed mechanism employed on the upstrokeside of the reducer.

In general, the wood reducer of my invention comprises a disc-shapedrotor having a plurality of knives mounted on its face and extending apredetermined distance outwardly therefrom. While the rotor is driven ata selected rotary speed, wood is fed against it by multiple feed meansarranged at a predetermined angular spacing from each other. Suitablehold down means are employed for stabilizing the wood as the knives outagainst it in one direction on one side of the apparatus and in theopposite direction on the other sde of the apparatus, thereby insuringthe reduction of the wood to flakes of uniform size.

In FIGS. 1 and 3 there is depicted a rotary disc wood reducer driven bya motor which drives through belt 12 a shaft or arbor 14 journaled inbearings 16, 18 and mounting a vertical disc 20. The latter is ofsubstantial dimensions, being several feet in diameter, and mounts aplurality of knives 22. These extend outwardly from the face of the disca distance which determines the approximate thickness of the pieces tobe cut. They may be mounted adjus-tably as required to extend or retractthem to any desired degree. of projection.

The entire disc assembly is contained in a housing 24. Flakes or chipsproduced by the knives pass through the 3,101,756 Patented Aug. 27, 1963face of the disc and are discharged from the bottom of the housing asindicated in FIG. 3. Wood billets to be fed to the reducer are broughtin on belt 26.

When disc 20 is mounted vertically, as is preferred, two horizontallydisposed wood feeding assemblies 30, 32 may be arranged at substantiallyto each other on opposite sides of the disc. As a consequence, theknives will cut downwardly on the wood on one side of the apparatus andupwardly against it on the other side. More than two feeding assembliesmay be employed if desired, however, arranged at a predetermined angularspacing from each other about the disc.

Each feed unit contains essentially the same components, i.e. a hopperfor receiving wood billets, means for driving the wood against the disc,means for holding the wood down and stabilizing it as it is reduced, andanvil means against which the knives in the disc work. However, thearrangement of these components differs on the downstroke and upstnokesides of the apparatus.

The construction of the wood feed assembly on the downstroke side of theapparatus is shown in FIGS. 1 and 2. Its elements are housed in ahorizontal frame 34 and a vertical frame 36. A hopper 38 is positionedfor guiding the Wood pieces in the direction of disc 20 in approximatelythe 3 oclock position when the disc rotates in a clockwise direction asviewed from in front. The pieces are pushed against the disc by a fluidoperated ram, preferably an hydraulic ram, the cylinder of which isindicated at 40 and the piston rod at 42. A crosshead 44 having a widthapproximating the length of the wood pieces to be reduced slides on abase 46 in the forward margin of which is seated a renewable anvil 48.

Cross head 44 is provided with spaced, forwardly projecting fingers 50,the ends of which contact the work and drive it across anvil 48 againstdisc 20. The rate at which this is accomplished may be determined by therate at which the wood is severed from the feed, the substantial forceof the ram advancing the piece by increments as each flake is cut awayby the knives. Thus the feed is metered automatically, although ifdesired the rate of advancement of the ram may be synchronized with thetheoretical rate of reduction of the wood piece as determined by knifeprojection and rotor speed.

Hold down means are provided for stabilizing the wood as it is reduced.In the illustrated form of the invention, the stabilizing hold downcomponent is housed in vertical frame 36. It comprises a constantpressure air cylinder- 52, to the piston rod of which is connected acrosshead 54 working in guideway 56.

A plurality of spaced, vertical fingers 58 extend downwardly from thecrosshead. These are interleaved with fingers50 of ram crosshead 44whereby the hold down head is movable toward the base to an inwardposition wherein the distance between the ends of fingers 58 and thebase is less than the corresponding thickness of the ram head fingers.The lower rearward working surfaces of the fingers 58 are angled toprovide a guiding surface 60 which cooperates with the ram in drivingthe pieces across anvil 48 and into the knife assembly. During thisoperation, the pressure exerted by air cylinder 52 provides a resiliencywhich enables the holddown to work effectively against pieces \ofirregular dimensions and random size, stabilizing them as they are fedinto the knives.

Irrespective of the stroke of cylinder 52 and of the diameter and shapeof the random sized billets constituting the feed, it is inevitable thatthe billets should become jammed fromtime to time as they are subjectedto the cooperating, but opposed, actions of ram fingers 50 andstabilizing holddown fingers 58. Accordingly, means are provided forquickly releasing billets which become jammed in this manner.

In the illustrated form of the invention, this objective is achieved bymounting cylinder 52 slidably in elements of vertical frame 36. Its basethen is connected to such means as a cam, crank, or, preferably, thepiston rod of a second cylinder 61. The latter cylinder may have a shortstroke, for example, a stroke of about 1 inch. During operation of theapparatus, the piston rod of cylinder 61 normally is extended. Then whenthe billets become jammed, it may be retracted. This withdrawsstabilizing fingers 58 and enables the operator quickly to clear themachine.

The wood feeding assembly 32 on the upstroke side of the apparatus isshown in detail in FIGS. 3 and 4. It corresponds essentially to that onthe downstroke side, with the exception that the feed stabilizing meansand anvil are arranged differently.

Thus feed assembly 32 is housed in a horizontal casing 62 and a verticalcasing 64. It includes a hopper 66 dimensioned and positioned forfeeding wood pieces crosswise to the rotor on the upstroke side, i.e. atapproximately the 9 oclock position. The pieces are advanced by a fluidoperated cylinder 67 which may be coupled to the driving elements by thecoupling arrangement illustrated in FIG. 3.

In this arrangement, the cylinder is mounted substantially horizontallyon a plane below that of the feed. Its piston rod is pivotally connectedto pivotally mounted, spaced, parallel, lever arms 68. The upper ends ofthe lever arms are slotted and slidably engage pins 69 extendinglaterally from the sides of a slide 70 extending rearwardly from acrosshead 72. Spaced fingers 74 extend forwardly of the crosshead anddrive the work beneath a segmental anvil 76 seated in a frame member.

In this instance, the stabilizing holddown assembly, housed in verticalcasing 64, is actuated by resilient air cylinder 78, the piston rod ofwhich is connected to a crosshead 80 working in a guide 82. The base ofcylinder 78 may be connected to the piostn rod of a short strokecylinder, not illustrated, which corresponds in operation and functionto cylinder 61 of FIG. 2, i.e. in releasing billets which inadvertentlybecome jammed as they are fed to the rotor.

A plurality of spaced, vertically arranged fingers 84 extend upwardlyfrom the crosshead. The leading upper surfaces 86 of these fingers areangled, like surfaces 60 of fingers 58, to guide the pieces against theanvil.

An alternate form of feedworks for use on the upstroke side of the discis illustrated in FIG. 5. Its construction is such as to permit use of aresilient stabilizing component located above the work, rather thanbelow it as in the case of the embodiment of FIGS. 3 and 4.

A hopper 90 feeds the work to a fluid-driven ram, the crosshead of whichis indicated at 92 and the forwardly projecting fingers of which areshown at 94. The ram advances the work across a sealing strip 96 andbeneath a bar 98 which serves the function of a secondary anvil.

The construction of the stabilizing holddown assembly is similar to thatshown in FIG. 2. A resilient air cylinder 100 pushes downwardly acrosshead 102 to which are attached a plurality of spaced, verticalfingers 104. These are interleaved with fingers 94 on rarn crosshead 92.

Their lower working surfaces are characterized by angled guidingsegments 106 and anvil segments 168. Hence as the wood is cut by knives22 moving upwardly, anvil segments 108 are employed primarily. However,any pieces in need of further reduction which pass behind and above theholddown fingers then are reduced by the action of the knives workingagainst secondary anvil 98.

Thus the present invention provides a disc-type, rotary wood reducer ofhigh capacity which can be fed by a single operator standing at astation defined by infeed conveyor 26, feed works 30, 32, and the rotarydisc cutter. The apparatus, furthermore, is highly efficient inproducing chips or uniform flakes of predetermined thickness from a feedwhich may comprise wood pieces of random diameter and non-uniformsurface.

It is to be understood that the forms of my invention herein shown anddescribed are to be taken as preferred examples of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of my invention or thescope of the subjoined claims.

Having thus described my invention, I claim:

1. A disc-type wood reducer for small pieces of wood comprising adisc-shaped rotor having a face surface, a plurality of knives mountedon the face surface of the rotor, means for driving the rotor, basemeans adjacent the rotor, a power operated feed ram on the base movableforwardly and rearwardly relative to the face of the disc and having ahead for engaging and driving wood pieces against the disc face, feedhopper means for directing wood pieces to the forward end of the ramhead when the latter is retracted, a holddown head movable in adirection substantially at right angles to the direction of travel ofthe feed ram, the holddown head and ram head having forward portionsarranged to interleave so that the holddown head is movable toward thebase to an inward position wherein the distance between the holddownhead and the base is less than the corresponding thickness of the ramhead, and means for moving the holddown head toward the base.

2. The disc-type wood reducer of claim 1 wherein the ram feed head andthe holddown head each includes a plurality of spaced fingers, thefingers of the holddown head being arranged to interleave with thefingers of the ram feed to permit the former to move to said inwardposition.

3. The disc-type wood reducer of claim 1 wherein the means for movingthe holddown head comprises resilient power means.

4. The disc-type wood reducer of claim 3 including reciprocativeadvancing and retracting means connected to the resilient holddown headpower means for retracting the latter to release jammed wood pieces.

5. The disc-type wood reducer of claim 1 wherein a rearward side of theholddown head is angled toward the base in the direction of forwardmovement of the feed ram.

6. A disc-type wood reducer comprising a disc-shaped rotor having aplurality of knives mounted on its face and extending a predetermineddistance outwardly therefrom, means for driving the rotor at apredetermined rotary speed, a plurality of wood feed means arranged at apredetermined spacing from each other around the rotor for feeding woodpieces against the rotor face, the knives cutting in one direction onwood pieces fed to one side of the rotor and in the opposite directionon wood pieces fed to the opposite side of the rotor, means forstabilizing the wood pieces as they are advanced against the rotor andreduced thereby, the stabilizing means comprising a plurality of spacedfingers having rearward work-guiding segments and forward anvilsegments, and means for urging the fingers resiliently against the woodpieces.

7. A disc-type wood reducer comprising a disc-shaped rotor having aplurality of knives mounted on its face and extending a predetermineddistance outwardly therefrom, means for driving the rotor at apredetermined rotary speed, a plurality of wood feed means arranged at apredetermined spacing from each other around the rotor for feeding woodpieces against the rotor face, the knives cutting in one direction onwood pieces fed to one side of the rotor and in the opposite directionon wood pieces fed to the opposite side of the rotor, means forstabilizing the Wood pieces as they are advanced against the rotor andreduced thereby, the stabilizing means comprising a plurality of spacedfingers having working surfaces including rearward Work-guiding segmentsand forward anvil segments, the fingers being interleaved with 5 T aplumli ty of fingers provided on the wood feed means 2,811,183 and beingurged resiliently against the wood pieces for 2,889,859 stabilizing thesame.

References Cited in the file of this patent 5 16,931 UNITED STATESPATENTS 2,299,248 Ottersland Oct. 20, 1942 1134060 2,796,094

Himmelheber June 18, 1957 v 6 Mottet Oct. 29, 1957 Johnson June 9, 1959FOREIGN PATENTS I Great Britain of 1890 Great Britain Nov. 3, 1932Germany Sept. 26, 1957 France Nov. 26, 1956

1. A DISC-TYPE WOOD REDUCER FOR SMALL PIECES OF WOOD COMPRISING ADISC-SHAPED ROTOR HAVING A FACE SURFACE, A PLURALITY OF KNIVES MOUNTEDON THE FACE SURFACE OF THE ROTOR, MEANS FOR DRIVING THE ROTOR, BASEMEANS ADJACENT THE ROTOR, A POWER OPERATED FEED RAM ON THE BASE MOVABLEFORWARDLY AND REARWARDLY RELATIVE TO THE FACE OF THE DISC AND HAVING AHEAD FOR ENGAGING AND DRIVING WOOD PIECES AGAINST THE DISC FACE, FEEDHOPPER MEANS FOR DIRECTING WOOD PIECES TO THE FORWARD END OF THE RAMHEAD WHEN THE LATTER IS RETRACTED, A HOLDOWN HEAD MOVABLE IN A DIRECTIONSUBSTANTIALLY AT RIGHT ANGLES TO THE DIRECTION OF TRAVEL OF THE FEEDRAM, THE HOLDDOWN HEAD AND RAM HEAD HAVING FORWARD PORTIONS ARRANGED TOINTERLEAVE SO THAT THE HOLDDOWN HEAD IS MOVABLE TOWARD THE BASE TO ANINWARD POSITION WHEREIN THE DISTANCE BETWEEN THE HOLDDOWN HEAD AND THEBASE IS LESS THAN THE CORRESPONDING THICKNESS OF THE RAM HEAD, AND MEANSFOR MOVING THE HOLDDOWN HEAD TOWARD THE BASE.